Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32

J. Sunayama, Y. Ando, N. Itoh, A. Tomiyama, K. Sakurada, A. Sugiyama, Dongchon Kang, F. Tashiro, Y. Gotoh, Y. Kuchino, C. Kitanaka

Research output: Contribution to journalArticle

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Abstract

Bcl-2 homology domain (BH) 3-only proteins of the proapoptotic Bcl-2 subfamily play a key role as initiators of mitochondria-dependent apoptosis. To date, at least 10 mammalian BH3-only proteins have been identified, and it is now being realized that they have different roles and mechanisms of regulation in the transduction of apoptotic signals to mitochondria. Hrk/DP5 is one of the mammalian BH3-only proteins implicated in a variety of physiological and pathological apoptosis, yet the molecular mechanism involved in Hrk-mediated apoptosis remains poorly understood. In an attempt to identify cellular proteins participating in Hrk-mediated apoptosis, we have conducted yeast two-hybrid screening for Hrk-interacting proteins and isolated p32, a mitochondrial protein that has been shown to form a channel consisting of its homotrimer. In vitro binding, co-immunoprecipitation, as well as immunocytochemical analyses verified specific interaction and colocalization of Hrk and p32, both of which depended on the presence of the highly conserved C-terminal region of p32. Importantly, Hrk-induced apoptosis was suppressed by the expression of p32 mutants lacking the N-terminal mitochondrial signal sequence (p32(74-282)) and the conserved C-terminal region (p32 (1-221)), which are expected to inhibit binding of Hrk competitively to the endogenous p32 protein and to disrupt the channel function of p32, respectively. Furthermore, small interfering RNA-mediated knockdown of p32 conferred protection against Hrk-induced apoptosis. Altogether, these results suggest that p32 may be a key molecule that links Hrk to mitochondria and is critically involved in the regulation of Hrk-mediated apoptosis.

Original languageEnglish
Pages (from-to)771-781
Number of pages11
JournalCell Death and Differentiation
Volume11
Issue number7
DOIs
Publication statusPublished - Jul 1 2004

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Porins
Mitochondrial Proteins
Apoptosis
Proteins
Mitochondria
Protein Sorting Signals
Immunoprecipitation
Small Interfering RNA
Signal Transduction
Yeasts

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Cell Biology

Cite this

Sunayama, J., Ando, Y., Itoh, N., Tomiyama, A., Sakurada, K., Sugiyama, A., ... Kitanaka, C. (2004). Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32. Cell Death and Differentiation, 11(7), 771-781. https://doi.org/10.1038/sj.cdd.4401418

Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32. / Sunayama, J.; Ando, Y.; Itoh, N.; Tomiyama, A.; Sakurada, K.; Sugiyama, A.; Kang, Dongchon; Tashiro, F.; Gotoh, Y.; Kuchino, Y.; Kitanaka, C.

In: Cell Death and Differentiation, Vol. 11, No. 7, 01.07.2004, p. 771-781.

Research output: Contribution to journalArticle

Sunayama, J, Ando, Y, Itoh, N, Tomiyama, A, Sakurada, K, Sugiyama, A, Kang, D, Tashiro, F, Gotoh, Y, Kuchino, Y & Kitanaka, C 2004, 'Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32', Cell Death and Differentiation, vol. 11, no. 7, pp. 771-781. https://doi.org/10.1038/sj.cdd.4401418
Sunayama, J. ; Ando, Y. ; Itoh, N. ; Tomiyama, A. ; Sakurada, K. ; Sugiyama, A. ; Kang, Dongchon ; Tashiro, F. ; Gotoh, Y. ; Kuchino, Y. ; Kitanaka, C. / Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32. In: Cell Death and Differentiation. 2004 ; Vol. 11, No. 7. pp. 771-781.
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